Thyristor housing assembly

ABSTRACT

A disk-shaped gas tight thyristor housing assembly is provided which consists of a housing formed of an insulating ring shaped wall and two metal cover plates with a thyristor mounted therein. The thyristor is pressed between a metal plate which engages the cathode ring electrode and one of the cover plates which engages the anode electrode. The control lead to the ignition electrode, which is centrally located in the upper surface of the thyristor extends through the ring shaped wall, then through insulating tube lying in a groove which engages the cathode ring electrode, then into an insulating tubular compartment which is located in a centrally located well in the under surface of the plate, which engages the cathode ring electrode. The inner end of the ignition control lead terminates in a downwardly extending coil which engages the ignition electrode. The upper portion of the coil backs an insulating cap which closes off the inner end of the well. At least the coil portion of the control lead is formed of springy material, such as beryllium bronze.

United States Patent Bahlinger et al.

[ THYRISTOR HOUSING ASSEMBLY [75] Inventors: Walter Bahlinger; Werner Egerbacher; Heinz Martin, all of Munich, Germany [73] Assignee: Siemens Aktiengesellschaft, Berlin & Munich, Germany [22] Filed: Sept. 14, 1973 [21] Appl. No.: 397,403

Primary ExaminerMichael J. Lynch Assistant ExaminerE. Wajciechowicz Attorney, Agent, or FirmHill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson 1 1 May 27, 1975 [57] ABSTRACT A disk-shaped gas tight thyristor housing assembly is provided which consists of a housing formed of an insulating ring shaped wall and two metal cover plates with a thyristor mounted therein. The thyristor is pressed between a metal plate which engages the cathode ring electrode and one of the cover plates which engages the anode electrode. The control lead to the ignition electrode, which is centrally located in the upper surface of the thyristor extends through the ring shaped wall, then through insulating tube lying in a groove which engages the cathode ring electrode, then into an insulating tubular compartment which is located in a centrally located well in the under surface of the plate, which engages the cathode ring electrode. The inner end of the ignition control lead terminates in a downwardly extending coil which engages the ignition electrode. The upper portion of the coil backs an insulating cap which closes off the inner end of the well. At least the coil portion of the control lead is formed of springy material, such as beryllium bronze.

3 Claims, 2 Drawing Figures I THYRISTOR HOUSING ASSEMBLY BACKGROUND OF THE INVENTION The field of the present invention relates to thyristor housing assemblies and particularly to the nature of the housing and to the manner which electrical contact is made with the various electrodes of the thyristor. It has been suggested in the past that a thyristor might be mounted in a disc-shaped housing formed of an insulating ring-shaped wall portion closed at both ends by metal discs. The thyristor mounted within the housing had its anode electrode and its cathode electrode engaged respectively by the metal discs thereby to provide external lead connections to the anode and cathode of the thyristor. Connection to the ignition electrode was made by a wire extending through the ring shaped housing wall and, by leverage from the outside, was caused to press against the ignition electrode. This prior structure was found to have considerable disadvantages. The assembly of the control line to the ignition electrode was relatively complicated. The pressure of the control line on the ignition electrode was small on account of the length of the control line extending into the housing before it reached the control electrode. Furthermore, the direction of the slot in the upper metal plate had to agree with the direction of extension of the control line. The greatest disadvantage consisted in the fact that the pressure of the control line on the ignition electrode could not be set accurately.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel thyristor assembly which is simple to construct, has a stable assembly and assures that the pressure of the control line on the ignition electrode is sufficient and of the desired amount to assure satisfactory amount.

In particular, a disc-shaped gas tight thyristor housing assembly is provided which consists of a housing formed of an insulating ring shaped wall and two metal cover plates with a thyristor mounted therein. The thyristor is pressed between a metal plate which engages the cathode ring electrode and one of the cover plates which engages the anode electrode. The control lead to the ignition electrode, which is centrally located in the upper surface of the thyristor extends through the ring shaped wall, then through insulating tube lying in a groove which engages the cathode ring electrode, then into an insulating tubular compartment which is located in a centrally located well in the under surface of the plate which engages the cathode ring electrode. The inner end of the ignition control lead terminates in a downwardly extending coil which engages the ignition electrode. The upper portion of the coil backs an insulating cap which closes off the inner end of the well. At least the coil portion of the control lead is formed of springy material, such as beryllium bronze.

Means can be provided which clamps the control line to the upper metal plate. This means can consist of an elastic insulating ring which is located in the recess, whose outer diameter is somewhat greater than the recess and whose inner diameter is somewhat greater than the outer diameter of the spiral spring. The end of the control line which passes into the opening is expediently wave shaped and is elastically clamped in the opening. The slot is expediently arranged on the side of the metal plate which faces away from the semiconductor element.

Other objects, features claims advantages. as well as equivalent structures which are intended to be covered hereby, will become more apparent to those versed in the art in connection with the teaching of the principles of the present invention with the disclosure of the preferred embodiment in the specification, calims and drawings. in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a diagrammatic vertical view partly in section illustrating an embodiment of this invention; and

FIG. 2 is a diagrammatic plan view looking down on the upper face of the top metal plate with the housing removed.

DETAILED DESCRIPTION OF ONE EMBODIMENT The preferred embodiment of the present invention shown in FIGS. 1 and 2 of the drawings, comprises a disc-shaped gas tight housing consisting of a ringshaped wall 1 formed of an insulating material such as aluminum oxide which is closed at its two ends by metal cover plates 2 and 3. The metal cover plates 2 and 3 are soldered or welded to rings 4 and 5, which rings are connected to the insulating ring-shaped wall 1 by hard soldering. The rings 4 and 5 preferably are formed of metal whose thermal expansion coefficient is adapted to that of the ring-shaped wall 1. If the insulating ringshaped wall I is formed of aluminum oxide, for exam ple, the rings 4 and 5 may be of an iron-nickel-cobalt alloy which has become known under the trade name Kovar. A semiconductor thyristor 6 is mounted on the lower cover plate 3. This may be done by permanently soldering it into position or securing it by a press fit. It will be understood that when the semiconductor element 6 is a conventional type thyristor, it will include an anode electrode (not shown) on its under sur face, a ring-shaped cathode electrode (not shown) on its upper surface, and an ignition electrode (not shown) in the center of its upper surface in substantially the same plane as the ring-shaped cathode electrode. On the upper side of the thyristor 6 lies a metal plate 7 which has a recess or well 8 extending upwardly from its under surface. The recess 8 is centrally located. The upper surface of the metal plate 7 is seated against the cover plate 2 and makes electrical contact therewith.

Extending radially inwardly from the outer edge of the disc-shaped metal plate 7 is a slot 13. As may be seen from an inspection of FIGS. 1 and 2, this slot 13 extends an appreciable distance past the center of the disc 7 and beyond the boundary of the recess 8. The recess 8 is deep enough so as to open into the slot 13. As will be appreciated by those ordinarily skilled in the art, the upper metal plate 2 through the metal plate 7, pro vides the electrical connection to the cathode electrode of the thyristor 6. The lower metal cover plate 3 provides the electrical connection to the anode of the thyristor 6.

The control lead to the ignition electrode (not shown) is provided by a metal conductor 9 which extends through an insulating tube 16 lying in the bottom of the slot 13 and extending into the edge of the well 8. The inner end of the control line 9 is in the form of a coil spring projecting downwardly into the well 8 into spring pressed contact with the ignition electrode (not shown). The wall of the well 8 is provided with an insulating ring 12. The top of the well at the point where the control line 9 enters the vicinity of the well is closed off by an insulating plate 11. This insulating plate 11 presses down on the coil 10 which forms the inner end of the control line 9 into a pressure contact with the ignition electrode. The control line 9, at its outer end, extends into a socket which is mounted in a gas tight fit in the wall 1. The outer end of the control line 9 has a wavy shape in order to make a good contact with the inner wall of the tubular metal socket 15 which extends through the wall 1 in a gas tight fit. The socket 15 pro vides a suitable terminal connection for the ignition electrode. As may be understood best by viewing FIGv 2, the insulating plate 11 which covers the tubular insulating lining 12 of the recess 8, rests against parts of the metal plate 7, since the slot 13 is substantially less in width than the diameter of the insulating disc-shaped plate 11.

From the above description, it will be noted that the connection of the control electrode of the semiconductor element 6 to the housing is simple to execute. in the first place, insulating plate ll is inserted into the recess 8 in the metal plate 7. Then the control line 9 is introduced through the recess 8 into the slot 13 in such a manner that the spiral spring It) lies in the recess 8. The spiral spring 10 is clamped by means of the elastic insulating ring 12 in the recess 8. The control line 9 has been previously provided with the insulating tube 16. Then the plate 7 with its individual components is placed from above onto the semiconductor element 6 which has previously been inserted in the subsidiary housing consisting of the insulating ring-shaped wall member 1, the metal plate 3, and the metal ring 5. The spiral spring 10 projects somewhat beyond the under surface of the metal plate 7 in the unloading state, and is, therefore, pressed against the ignition electrode of the semiconductor element 6 when the upper cover plate 2 is placed in position. The pressure of the spring 10 is determined by its spring constant and the pitch of the spring, and both values may be relatively accurately adhered to. Then the metal plate 7 is placed in position, and the end 14 of the control line 9 is simultaneously threaded into the opening of the socket 15 where it is elastically held. The cover plate 2 can be connected subsequently with the metal ring 4 to the insulating ring-shaped wall 1. it is preferable that the control line 9 consists of a good conductive springy metal such as beryllium bronze.

it will be apparent to those skilled in the art that many modifications and variations may be effected without departing from the spirit and scope of the novel concepts of the present invention.

We claim as our invention:

1. A thyristor with a disc-shaped housing comprising an insulating ring, two metal cover plates connected in gas tight fashion to said ring, a semiconductor element having an ignition electrode, a control line having one end passing into an opening in said housing, and its other end resting on said ignition electrode, a metal plate arranged between one of the cover plates and said semiconductor element, said metal plate having a recess for the other end of said control line, one of the metal housing components having a slot therein in which is arranged at least a part of the control line, in said slot opening into said recess, said recess being provided with an abutment on said metal plate facing said semiconductor element, the end of the control line which rests on said ignition electrode being designed as a coil spring disposed in compression against said igniton electrode and against said abutment, and means for clamping said control line inclcuding said spring to said metal plate including an elastic insulating ring having an outer surface in engagement with the surface of said recess and an inner surface embracing said spring, and an insulating cap between said spring and said abutment.

2. A thyristor with a disc-shaped housing as set forth in claim 1, in which said slot lies on the side of said metal plate which faces away from said semiconductor element.

3. A disc-shaped gas tight thyristor housing assembly comprising an insulating ring-shaped wall, a conductive socket extending in gas tight relation through said ring shaped wall, said socket being closed at its outer end and being open at its inner end, top and bottom discshaped end plates, a pair of mounting flanges secured respectively to said end plates and to said ring-shaped wall. an intermediate metal plate below said upper end plate and in electrical contact therewith, a thyristor having anode, cathode and ignition electrodes between said intermediate plate and the lower of said end plates, said intermediate plate having a centrally located cav ity in its lower surface, said intermediate plate having a slot in its upper surface extending radially inwardly from its outer edge to a point beyond said cavity and in communication therewith, said intermediate plate providing electrical contact with said cathode electrode, said lower end plate having electrical contact with said anode electrode, a Control line extending radially inwardly through said ring-shaped wall, along the length of said slot to a point within said cavity, an insulating tube surrounding said control line where said control line is located in said slot, an insulating ring lining said cavity, the inner end of said control line terminated in a downwardly extending coil of springy electrical conductive material into contact with said ignition electrode and embraced by said insulating ring an insulating cap closing the inner end of said cavity and against which the upper end of said coil abuts compressing said coil against said ignition electrode within said cavity, and said control line extending into said socket and in pressure contact therewith. 

1. A thyristor with a disc-shaped housing comprising an insulating ring, two metal cover plates connected in gas tight fashion to said ring, a semiconductor element having an ignition electrode, a control line having one end passing into an opening in said housing, and its other end resting on said ignition electrode, a metal plate arranged between one of the cover plates and said semiconductor element, said metal plate having a recess for the other end of said control line, one of the metal housing components having a slot therein in which is arranged at least a part of the control line, in said slot opening into said recess, said recess being provided with an abutment on said metal plate facing said semiconductor element, the end of the control line which rests on said ignition electrode being designed as a coil spring Disposed in compression against said igniton electrode and against said abutment, and means for clamping said control line inclcuding said spring to said metal plate including an elastic insulating ring having an outer surface in engagement with the surface of said recess and an inner surface embracing said spring, and an insulating cap between said spring and said abutment.
 2. A thyristor with a discshaped housing as set forth in claim 1, in which said slot lies on the side of said metal plate which faces away from said semiconductor element.
 3. A disc-shaped gas tight thyristor housing assembly comprising an insulating ring-shaped wall, a conductive socket extending in gas tight relation through said ring-shaped wall, said socket being closed at its outer end and being open at its inner end, top and bottom disc-shaped end plates, a pair of mounting flanges secured respectively to said end plates and to said ring-shaped wall, an intermediate metal plate below said upper end plate and in electrical contact therewith, a thyristor having anode, cathode and ignition electrodes between said intermediate plate and the lower of said end plates, said intermediate plate having a centrally located cavity in its lower surface, said intermediate plate having a slot in its upper surface extending radially inwardly from its outer edge to a point beyond said cavity and in communication therewith, said intermediate plate providing electrical contact with said cathode electrode, said lower end plate having electrical contact with said anode electrode, a control line extending radially inwardly through said ring-shaped wall, along the length of said slot to a point within said cavity, an insulating tube surrounding said control line where said control line is located in said slot, an insulating ring lining said cavity, the inner end of said control line terminated in a downwardly extending coil of springy electrical conductive material into contact with said ignition electrode and embraced by said insulating ring an insulating cap closing the inner end of said cavity and against which the upper end of said coil abuts compressing said coil against said ignition electrode within said cavity, and said control line extending into said socket and in pressure contact therewith. 